﻿Shader "Custom/AlphaBlend"
{
    Properties
    {
        _Color("Main Tint",Color) = (1,1,1,1)
        _MainTex("Main Tex",2D) = "white"{}
        _AlphaScale("Alpha Scale",range(0,1)) = 1 
    }
    
    SubShader
    {
        Tags{"Queue" = "Transparent" "IgnoreProjector" = "True" "RenderType" = "Transparent"}
        pass
        {
            Tags{"LightMode" = "ForwardBase"}
            ZWrite off
            Blend SrcAlpha OneMinusSrcAlpha            
            
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "Lighting.cginc"
            
            fixed4 _Color;
            sampler2D _MainTex;
            float4 _MainTex_ST;
            fixed _AlphaScale;
            struct a2v
            {
                float4 vertex:POSITION;
                float3 normal:NORMAL;
                float4 texcoord:TEXCOORD;
            };
            
            struct v2f 
            {
                float4 pos:SV_POSITION;
                float3 worldNormal:TEXCOORD0;
                float3 worldPos:TEXCOORD1;
                float2 uv:TEXCOORD2;
            };
            
            v2f vert(a2v v)
            {
                v2f o;
                o.pos = UnityObjectToClipPos(v.vertex);
                o.worldNormal = UnityObjectToWorldNormal(v.normal);
                o.worldPos = mul(unity_ObjectToWorld,v.vertex).xyz;
                o.uv = TRANSFORM_TEX(v.texcoord,_MainTex);
                return o;
            }
            
            fixed4 frag(v2f i):SV_Target
            {
                fixed3 worldNormal = normalize(i.worldNormal);
                fixed3 worldLightDir = normalize(UnityWorldSpaceLightDir(i.worldPos));
                
                fixed4 texColor = tex2D(_MainTex,i.uv);
                fixed3 albedo = texColor.rgb * _Color.rgb;
                fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz * albedo;
                fixed3 diffuse = _LightColor0.rgb * albedo * max(0,dot(worldNormal,worldLightDir));
                return fixed4(ambient + diffuse,texColor.a * _AlphaScale);
            }
            ENDCG  
        }
    }
}
